Project Summary The long-term goals of this project are to develop new small molecules that can be used to control K2P potassium channel function and that will be able to label K2P channels so that they can be imaged in cells and in vivo. K2Ps are responsible for ?leak? potassium currents that are pivotal in modulating the excitability of neurons. Members from this diverse potassium channel family respond to varied stimuli that include pH changes, temperature, and mechanical force. K2P channels have well-established roles in the nervous and cardiovascular systems and are implicated in pain, anesthetic responses, thermosensation, and mood, but remain the least well-understood potassium channel class. Ion channels are highly desirable drug targets as they are readily accessible to extracellular compounds and their modulation brings about rapid changes in excitable cell function in the heart and brain. Nevertheless many channels, including all K2P family members, lack pharmacological agents that can selectively affect function. This lack of pharmacological control creates a serious deficiency in our ability to understand, probe, and impact K2P in vivo function. We seek to address this fundamental gap by building on recent discoveries from our laboratory that define a novel small molecule binding site in the mechano- and thermo-sensitive TREK K2P subfamily that is important for pain, analgesic responses, and mood. We will leverage a multidisciplinary approach that includes structure-guided small molecule design together with structural and electrophysiological measurements to create new, selective chemical agents that can be used to probe K2P activity. Because of their important roles in human physiology, K2Ps are targets for drugs for the treatment of chronic pain, stroke, and depression. Thus, developing new small molecules that affect K2P channel function should not only provide powerful tools for dissecting in vivo activity of K2Ps but should aid in the development of new therapeutic agents for a range of human diseases.